WTF this ? does he think children are just tools of war?
Well yeah. It's already been shown that he's a narcissist and a sociopath. For someone like this? Everyone, no matter of their age, status, or gender, is just a tool for him to use however he wishes to.
His ultimate goal is to be the last hero, ever, so that he will be remembered as the undisputed number one throughout history.
But you'll never catch me saying such people are, by default, some kind of genius, because his plan has a fatal flaw that any five year old child can point out.
The only way to be absolutely certain of that outcome, after achieving his "strongest hero" status, would be to destroy all living beings in their world so that there'd be absolutely no chance of anyone better than him ever appearing. Because there's no way to guarantee that there will never be a conflict in the future that will spur the development of such a hero ever again, no matter how much he hamstrings their society to prevent it.
But the really bad part about this is if he ever realizes it, then he'll be more than happy to follow through on it. This is what makes sociopathic narcissists so dangerous to deal with. It doesn't matter how wrong something is - they will do everything that is needed to assure their goals, no matter what.